Passive Ultra High Frequency RFID sensor with reference tag for crack detection of aluminum alloy structure

Abstract

It can be ensured safe and reliable operation of a metallic structure by monitoring the positions which are easy to crack. Because the channel changes with the environment, a tag sensor in the ultra high frequency (UHF) is vulnerable to interference. This paper aims to investigate the reliability of passive RFID sensor systems with a reference tag for crack detection of aluminum alloy structures when the condition of reading distance and surrounding environment changes. The impedance and gain of tags are simulated, which provides theoretical basis for experimental analysis. With an increase of crack depth, the impedance of the sensor tag shifts to the low frequency direction, and the reference tag changes slightly. When dual tags are placed orthogonally, the gain of the sensor tag changes greatly, which means that it is more sensitive to crack depth. The backscatter power of the sensor tag shows a decline trend, and the power of the reference tag remains unchanged. The sensor features a linear response with the variation of crack depth. The sensitivity of crack characterization is better when dual tags are placed orthogonally.

A Concise State-of-the-Art Review of Crack Monitoring Enabled by RFID Technology

“…Because the label is flexible, it can be covered with a curved metal surface. On the other hand, Wang et al [51] studied the reliability of a passive RFID sensor system with a reference tag in aluminum alloy structural crack detection under conditions of varying reading distance and ambient changes. As the crack depth increases, the sensor tag impedance shifts to the low-frequency direction, and the gain of the proposed sensor exhibits greater sensitivity to variations in crack depth.…”

A Review of Radio Frequency Identification Sensing Systems for Structural Health Monitoring

“…With a circular patch antenna as a crack sensor, a linear relationship between the resonance frequency and crack parameters, i.e., depth, length, width, and cross-sectional area, has been obtained [ 8 ]. A rectangular patch antenna was developed for crack depth and length detection with mm resolution [ 9 , 68 , 69 , 70 , 71 ]. Crack localization [ 69 ] and multi-tag coupling [ 9 , 70 ] were further investigated.…”